Efficacy of Vitamin K₂ for Glucocorticoid-induced Osteoporosis in Patients with Systemic Autoimmune Diseases

抄録

Objective Vitamin K₂ (menatetrenone) is an effective treatment for patients with postmenopausal osteoporosis. We herein performed a subanalysis of patients with systemic autoimmune diseases undergoing glucocorticoid therapy in our previous prospective study.

Methods Sixty patients were categorized into a group with vitamin K₂ treatment (n=20, Group A) and a group without vitamin K₂ treatment (n=40, Group B). All patients were treated with bisphosphonates.

Results Serum levels of osteocalcin and undercarboxylated osteocalcin decreased significantly after the start of glucocorticoid therapy in both groups, while the serum osteocalcin level was significantly higher in Group A than Group B during the third (p=0.0250) and fourth weeks (p=0.0155). The serum level of the N-terminal peptide of type I procollagen, a bone formation marker, decreased during glucocorticoid therapy, but was significantly higher in Group A than Group B during the fourth week (p=0.0400). The bone mineral density and fracture rate showed no significant differences between the two groups.

Conclusion Although vitamin K₂ improves bone turnover markers in patients with osteoporosis on glucocorticoid therapy, it has no significant effect on the bone mineral density and fracture rate after 1.5 years of treatment.